Due to the opportunity for afforestation in South Africa being severely limited, extensive research is being carried out on obtaining more wood per given area, improving the quality and value of the wood and on gaining a better understanding of how wood properties influence the characteristics of the pulp it produces. The last mentioned is the main focus of this study. If the variations in pulp, due to variations in wood properties, are better understood, then the existing fibre resource could be more efficiently managed and utilised to maximise its value. The main objective of this study was to determine how variation in physical and chemical properties, from the existing P.patula resource drives variation in pulp strength properties. It is well known that differences in tree age and site index lead to major sources of variation of various wood properties. These two easily measured variables were used in this study to capture a significant amount of variation in the wood of the aforementioned genus that enters a mill. Samples were obtained from two extremes in site quality, as measured by site index, (viz. good and poor sites) and three age ranges (viz. 9-10 years, 13-14 years and 20-21 years) from the KwaZulu-Natal Midlands. Wood chips from each of the six sites were pulped for various lengths of time, using the Kraft pulping method and under the same pulping conditions. A wide range of anatomical and chemical properties of wood and pulp were measured to characterise these samples as extensively as possible. All pulp samples were beaten in a PFI mill, at four different levels. The freeness values of the beaten samples were measured. The physical properties measured on handsheets made from the pulp included sheet density, burst index, tear index, tensile index, tensile energy absorbed, stretch and zero-span tensile strength. Regression models were developed to quantify the impact of the measured variables on each of the strength properties. Principal component analysis was performed on the wood characteristics measured and indicated that tree age is a more critical source of variation in wood properties than site index. The predictions of whole tree wood properties from the properties measured at breast height were excellent. Pulping studies showed that pulp yield, at kappa 20-30, increased with tree age. Wood cellulose proved to be a very good predictor of pulp yield. Xylose and mannose appeared to be most resistant to degradation during pulping. The low yield pulps were easier to refine than those with high yield. This has important implications when considering high yield pulping processes. With regard to pulp strength, the younger material could not achieve the high tear strengths obtained by the older material. However, the tear strengths achieved by these younger sites were comparable with, if not higher than, that obtained by hardwood species. The implications of this is that younger P. patula trees could be used for grades of paper where very high tear strength is not essential, but tensile is (e.g. tissue paper) and that older material can be better used for the purpose of providing the high tear strength needed by certain paper grades (e.g. linerboard and sackkraft). The maximum tensile strength achieved by the younger material was higher than that of the older material. When compared at constant freeness or sheet density, longer cooking times had a deleterious effect on strength properties. Strong predictions of pulp strength from basic wood properties were obtained when strength results were compared at constant freeness and sheet density. Because of the great influence of fibre morphology and chemistry on refining rates and on the resultant strength properties, the results of the study suggest that fibres of greatly different chemical and anatomical characteristics should not be refined together, if beating energy and pulp strength are to be optimised. However, further work is required to evaluate if the separation of fibre resources, to improve pulp quality, would be economically viable. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2005.

Increment cores are invaluable for assessing tree attributes such as inside bark diameter, radial growth, and sapwood area. However, because trees accrue growth and sapwood unevenly around their pith, tree attributes derived from one increment core may not provide sufficient precision for forest management/research activities. To assess the variability in a tree’s inside bark radius, sapwood radius, and 10-year radial growth estimated by tree cores, two increment cores at 90 degree angles were collected from ponderosa pine (Pinus ponderosa) trees in eastern Montana (n = 2,156). Paired core measurements varied substantially with 13% mean difference for inside bark radius, 19% mean difference for sapwood radius, and 23% mean difference for estimates of radial increment. Furthermore, decreasing crown ratio, decreasing diameter, and increasing site slope were all found to increase differences in estimates derived from paired cores. Whether for management or research purposes, the number of cores that should collected per tree depend on a stand’s susceptibility to reaction wood, required measurement precision, and budgetary constraints.

Les techniques de culture du pin maritime dans les Landes de Gascogne ont connu des changements importants à partir des années 1960. A côté de peuplements de sylviculture traditionnelle basée sur la régénération naturelle assistée, se sont succédés de nouveaux types de peuplements sous le vocable de « ligniculture ». La proportion de ces peuplements menés intensivement, dans la récolte des coupes rases en Aquitaine, va augmenter rapidement dans les dix prochaines années. Les données technologiques faisant actuellement défaut sur cette ressource, il est nécessaire d’anticiper dès aujourd’hui l’impact de ces pratiques sylvicoles sur les propriétés du bois.Des arbres ont été échantillonnés dans 14 parcelles réparties dans les Landes de Gascogne. Sur chaque parcelle, 4 arbres ont été sélectionnés pour les mesures des propriétés physiques. Les variations radiales de densité intra-cerne, de proportion de bois final, de duramen et d’angle du fil ont été mesurées. Parallèlement 8 arbres ont été exploités. Après sciage puis séchage, l’aspect visuel et les propriétés mécaniques des avivés obtenus ont été mesurés. Sur la base des données recueillies et de données d’études précédentes, des modèles déterministes ont été développés pour prédire les variations des caractéristiques étudiées. Ces modèles de la famille des modèles mixtes, sont constitués d’une partie « fixe » commune à l’ensemble des arbres et d’une partie aléatoire qui quantifie les écarts propres à la parcelle et aux arbres (appelés effet « parcelle » et effet « arbre »). Un modèle décrivant les variations avec la hauteur dans l’arbre du taux de duramen, basé sur l’âge des arbres a été développé, il explique plus de 70% de la variation. Les modèles décrivant les variations radiales de l’angle du fil, de la densité, et des propriétés mécaniques du bois ont un niveau de prédiction plus faible, mais un effet significatif de l'âge cambial et de la largeur de cerne sur ses propriétés a été mis en évidence. La vitesse de croissance a un impact négatif sur les propriétés mécaniques du bois de pin maritime.Appliqué à des scénarios sylvicoles ces modèles ont permis d'estimer le classement mécanique des sciages pouvant potentiellement être obtenus à partir de la ressource.Le transfert de ces modèles auprès des gestionnaires forestier pourrait permettre une meilleure estimation de la qualité des bois et donc leur meilleure allocation dans un contexte post tempête où la ressource en pin maritime en Aquitaine se fait rare. / The forest cultivation techniques of maritime pine in the South Western France deeply changed in the 1970’s. In particular the reforestation method shifted from assisted natural regeneration to intensive techniques including soil ploughing, phosphoric fertilization and seeding, then plantation with improved material in the 1980’s. As the proportion of “intensively cultivated” stands in final cut will increase drastically in the next decades, it is now necessary to anticipate the impact of these reforestation methods on the wood properties for the wood industry, from the analysis of the oldest.Trees were sampled from 14 stands in the South Western France covering a wide range of mean volume. On each stand, 4 trees were selected for physical properties measurement. Within ring wood density, latewood content, heartwood diameter and spiral grain angle were measured on wood disks collected at different heights within each tree. At the same time 8 trees were harvested and bucked into 2.2 m long logs. After drying, visual aspect and mechanical properties of the sawn boards were assessed.Based on the data, deterministic models were developed to predict the variables based on selected stand and tree characteristics. The models for heartwood content in cross section explain quite well the variation with height (more than 70% of the variation). The heights of green and dead branches were identified as important variables in the models for nature of knot in trees. The developed models, for spiral grain angle, radial variations of wood density and mechanical properties, have a relatively low level of prediction, but it has highlighted the effect of cambial age and ring width on these properties. The growth rate has so a negative impact on the mechanical properties of wood of maritime pine. Based on the mixed model analysis with repeated measurements structure, the trees and stand effect on the residual variation were estimated. Applied on silvicultural scenarios, these models have been used in a simplified approach to estimate the strength of timber that can potentially be obtained from the resource. The transfer of these models with forest managers could allow a better estimate of the quality of wood, and thus a better allocation in a post-storm context where the resource is scarce.

Several studies carried out in boreal forests have found significant edge effects in Scots pine although, none of them in southern Sweden. The aim of this study was to investigate edge effects in adjacent Scots pine stands and its influence on tree growth and field vegetation composition. This was carried out in 10 selected forest edges in southeastern Sweden. Results showed reduced number of stems, height, diameter and basal area growth among young trees in particular within 2 m from the forest edge. In the older stands number of stems, diameter and basal area growth increased within the first 2 m from the edge. Field vegetation inventory showed differences in composition in the adjacent stands. In the older stands lichens, lingonberry and blueberry were more frequent, while heather and grasses showed a higher appearance in young stands.

Les propriétés du bois de pin maritime varient aux niveaux chimique, anatomique et mécanique. Six types de bois peuvent être trouvés au sein d’un même arbre : bois précoce, bois tardif, bois de couronne, bois de base, bois de compression et bois opposé. Au cours de cette thèse, nous avons testé l’hypothèse selon laquelle la variabilité phénotypique des propriétés de bois, serait liée à l’expression différentielle des protéines lors de la xylogénèse. Par une approche protéomique basée sur l’électrophorèse bidimensionnelle et la spectrométrie de masse en tandem (LC ESI MS/MS), nous avons identifié 165 protéines différentiellement exprimées le long d’un gradient d’âge cambial (bois juvénile vs. bois mature) ainsi que 93 protéines différentiellement exprimées au cours de la saison de végétation (bois de printemps vs. bois d’été) chez le pin maritime. Une analyse chimique complémentaire des échantillons a été réalisée par pyrolyse analytique. Nos résultats montrent que le xylème secondaire formé en début de saison ainsi que celui qui est initié par un cambium jeune présentent une sur-expression de protéines participant à la division cellulaire. Dans le xylème issu d’un cambium âgé ou formé à la fin de l’été nous avons mis en évidence des protéines impliquées dans la défense cellulaire (dont le rôle serait de retarder la mort cellulaire programmée), ainsi que des protéines impliqués dans la biosynthèse des éléments constitutifs de la paroi. Cette étude contribue à renforcer nos connaissances sur les acteurs moléculaires intervenant lors de la xylogénèse. Elle ouvre par ailleurs des pistes de recherche sur la détection de gènes impliqués dans le contrôle génétique des propriétés du bois dans un objectif de sélection assisté par marqueurs. / Wood properties in maritime pine are highly variable at chemical, anatomical and mechanical levels. Six types of wood can be found in a single tree, early wood, late wood, crown wood, base wood, compression wood and opposite wood. In this thesis report, we tested the hypothesis that the observed variability at the phenotypic level, can be bound to the differential expression of proteins during the process of wood formation. We use the tools of proteomics, Bidimensional electrophoresis and LC ESI MS/MS for the discovery of 165 proteins differentially expressed in a cambial age gradient, (from base wood to crown wood), an 93 overexpressed proteins in a seasonal gradient (from early wood collected at the beginning of the growing season, to late wood, collected at summer) Complementary, chemical characterization of the samples was performed using analitycal pyrolisis. Our results showed that the secondary xylem formed at the beginning of the growing season, and the xylem formed by a young cambium, present a overexpression of proteins participating in the intense cell division, characteristical of those tissues, e.g. Biogenesis of cytoskeleton and hemicelluloses, RNA transcription, synthesis, folding and modification of proteins. In the xylem formed at the base of the trunk and at the end of the growing season we have found an over-expression of proteins from cell defense (they role will be to delay programmed cell death) and cell wall formation related proteins e.g. lignin biosynthesis. This study contributes to reinforce our knowledge over the molecular actors involved in the xylogenesis process. It opens, in another hand , research guides for the detection of genes involved in the genetic control of wood properties towards an objecive of marker assisted selection.

On 26 May 2003, intense rainfall from a series of thunderstorms in eastern North Carolina caused flooding that eventually destroyed the concrete dam in Hope Mills, draining Hope Mills Lake, and revealing a formerly submerged and buried structure that was identified as a timber crib dam. Inspection revealed these logs to be old-growth longleaf pines, which are now rare on the coastal plain landscape. Our primary objective was to develop a new multi-century longleaf pine tree-ring chronology by crossdating the tree rings from sections extracted from logs in the crib dam with an anchored tree-ring chronology created from nearby living longleaf pine trees. We also examined the climatic response in the longleaf pine trees to evaluate their potential for reconstructing climate. Using tree-ring measurements obtained from old-growth longleaf pines found at a nearby church, we were able to date the rings on 21 series representing 14 logs from the crib dam, spanning the years 1597 to 1825. Distorted sapwood in many of the logs prevented us from finding absolute cutting dates and lessened the strength of correlation during the period of overlap between the church series and crib dam series. Human disturbances, specifically related to the naval stores industry, likely influenced the growth-ring patterns of the crib dam pine samples, as well. Correlation analyses between the longleaf pine chronology and temperature, precipitation, Palmer Drought Severity Indices, and North Atlantic sea surface temperatures showed a significant response to cool and wet spring months.

Climate and longleaf pine (Pinus palustris P. Mill.) radial growth relationships have been documented within its southern and western distribution. However, knowledge of this relationship is lacking along its northern latitudinal range margin (NLRM). Based on the principles of ecological amplitude, limiting factors, and studies of coniferous species in eastern temperate forests of the U.S., we hypothesized that the radial growth of longleaf pine in mixed pine-hardwood forests is responding to winter temperatures in southeastern Virginia. Two longleaf pine chronologies were developed to determine the relationship between radial growth and monthly temperature, precipitation, and Palmer Drought Severity Index (PDSI) via response function analysis (RFA). Results at the 0.05 level yielded significant response function coefficients with a positive response to current winter temperature and precipitation and a negative response to prior August PDSI. In studies of climate and longleaf pine radial growth in other parts of its range, winter temperature and precipitation have not shared a significant positive association with radial growth. Instead current spring and summer precipitation usually share this positive association. These findings add more evidence to an emerging pattern suggesting that winter temperatures contribute to limiting the radial growth of temperate conifers at northern range margins in the Northern Hemisphere.

South Florida slash pine (Pinus elliottii var. densa) is the southernmost pine species in the United States and the foundation species of the globally endangered pine rockland communities in south Florida. To test if slash pine produces annual growth rings in the Lower Florida Keys, we counted the number of rings on samples collected from the North Big Pine Key site (NBP), which contained a fire scar from a known wildfire and a known date for hurricane-induced tree mortality (2006 or 2007). In addition, a crossdated tree-ring chronology (1871–2009) was developed from living trees and remnant wood found at the site and compared to divisional climate data to determine how the regional climate regime influences radial growth. Our analyses demonstrated that slash pine forms anatomically distinct, annual growth rings with the consistent year-to-year variability necessary for rigorous dendrochronological studies. Response-function and correlation analysis showed that annual growth of slash pine at NBP is primarily influenced by water availability during the growing season. However, no significant correlations were found between tree growth and the Atlantic Multidecadal Oscillation or the El Niño-Southern Oscillation. Our study reveals the potential of producing high-quality dendrochronological data in southern Florida from slash pine, which should prove useful in further studies on fire history and tree phenology and for assessing the projected impacts of impending climate change on the fragile pine rockland community.

The postglacial recolonization of northern Europe supposedly originated from Western Europe and the Russian Plain, however, recent molecular and macrofossil-based investigations suggest that the history may be more complex than previously thought. This study aims to investigate the genetic diversity and population structure of Scots pine from Scandinavia to Russia to re-evaluate its recolonization history, and to examine whether the pattern of spatial genetic diversity has any adaptive significance. Populations ranging from Norway to Russia were sampled and genotyped using genotyping-by-sequencing. The seedlings were freeze tested to provide an average degree of hardiness for every population. Eight hundred and thirty-two seedlings were analyzed, and 6,034 SNPs were recovered in these individuals after stringent filtering. Population structure was investigated using fastStructure and differentiation between populations was estimated with pairwise FST and analysis of molecular variance (AMOVA) to assess the genetic variability. Genetic diversity was measured as observed heterozygosity, H0, in populations, clusters and overall. Two genetic clusters were detected in the samples, one in Norway and Sweden and one in Russia. These clusters are weakly differentiated (FST = 0.01202) with only 0.66 % variation between them. Highest variation was found within populations (98.8 %) and the overall genetic diversity for all populations was high (Ho = 0.2573). The weak differentiation and high diversity are indicative of extensive gene flow between populations in this species. The composition of the clusters across the sampled area suggests a westward recolonization from the Russian Plain into Scandinavia, and a possible local origin of another polymorphism in Norway and Sweden. No clear relationship between cold hardiness and genetic variation was detected. The clinal variation in cold hardiness reflects local adaptation, and the difference between genetic and phenotypic variation is likely due to epigenetic regulation or polygenic inheritance. More extensive genome scan is needed to understand the genetic basis of local adaptation.

Programa de Doctorado: Desarrollo Sostenible Conservativo de Bosques Tropicales. Manejo Forestal y Turístico / En este trabajo se estableció una estrategia para la conservación intraespecífica de la especie Pinus caribaea Morelet var. caribaea Barret y Golfari, basado en la caracterización de la variabilidad existente a nivel morfológico, ecofisiológico y genético en áreas de distribución natural de la especie, evaluando un total de 8 poblaciones (Cajálbana, Marbajita, La Güira, La Jagua, Galalón, Vinales, Pinar del Río y Sabanalamar), además se tuvo en cuenta aspectos de su dinámica, así como los principales factores que han incidido en la pérdida de sus poblaciones naturales, indicando que el manejo inadecuado, los incendios forestales y el aprovechamiento forestal, han sido las causas fundamentales. En el estudio se muestra una amplia variabilidad a nivel morfológico y genético en la especie, así como la diferenciación de dos grupos entre poblaciones a partir de 22 variables, uno al NO y otro al NE, donde Galalón mostró características muy distintivas. Se definen las poblaciones de Sabanalamar y La Güira como unidades de conservación, Galalón, como unidades significativas de evolución, Cajálbana, Marbajita, La Jagua y Vinales como unidades de manejo y una nueva categoría para la especie (unidades especiales de conservación) relacionada con su programa de mejoramiento genético.